A fluorescent endoscope is an imaging system for imaging blood flow, by imaging fluorescence radiation emitted by a fluorescence agent (e.g., a dye) illuminated by light generated by a fluorescent light source. Such an endoscope may be employed, for example, during surgery for visualizing the blood flow, and for evaluating tissue perfusion. In some cases, an additional visible light image of the observed area may be employed to provide anatomical reference to the fluorescent image.
In known in the art techniques in which both visible and fluorescent light are employed, the fluorescence image and white light image are acquired through the same channel of an endoscope (either in 3D or 2D imaging modes). In other words, two dissimilar imaging modalities are transmitted over the same channel of an endoscope. Although in such known in the art techniques the registration between the two images is simplified, the image acquisition is either interspersed in time (i.e., only white light image or fluorescent image are acquired at a time) or the white illumination is substantially attenuated to allow the relatively weaker fluorescence signal to be brighter than the background white light image.
U.S. Pat. No. 8,810,631 to Scott et al, entitled “Augmented stereoscopic visualization for a surgical robot using a captured visible image combined with a fluorescence image and a captured visible image” directs to an endoscope system which includes image capture system and a combination light source. The combination light source produces white light and at least one fluorescence excitation light. The imaging system captures light returned from tissue of a patient. According to one embodiment directed to by Scott et al, the imaging system includes 2 Charge Coupled Device (CCD) sensors. One CCD sensor captures an image of the white light only and the other CCD sensor captures an image of both white and fluorescent light. A processor processes the acquired images to generate a 3D stereoscopic image of both white light and fluorescent light.